Over time, chips have become increasingly complex and dense, as processors, memory circuits and other semi-conductors have gained greater capacity. Memory circuits, in particular, and all circuits with small features, in general, have become denser. Patterns for these circuits have become even more complex than the circuits, as optical proximity and laser proximity correction features have been added to the patterns. The equipment and writing strategies have become increasingly sophisticated, in response to requirements for smaller features on chips and tighter critical dimensions.
A considerable amount of design data to be presented to a pattern generator, for instance a mask writer or a direct writer (maskless writer) is heavily slivered. A great deal of object/feature in design data, for instance CIF™, OASIS™, Applicon™, DXF™, MEBES™ or GDS-II™), is divided into several sub objects/features: These sub objects/features are created because said object/features comprise numerous jogs defining optical proximity and laser proximity corrections. A sub object/feature with a certain aspect ratio is defined as a sliver. Slivers make the processing of design data more, for not saying extremely, compute intensive and for the time being there are no mask writers or maskless writers, which benefit from the appearance of said slivers, yet said slivers are generated. A certain feature with a plurality of slivers will in total have an unnecessary large circumference, as all slivers are treated as an object to be printed. Treating numerous slivers will increase the total writing time for a raster pattern generator, for instance Micronic Sigma7300 or Micronic Omega6600, which is a problem. For a Vector shape beam pattern generator, for instance JEOL JBX-3030MV, there is also a problem with slivers since too narrow slivers will create CD (critical dimension) variations. If the slivers become small enough they are impossible to write with VSB pattern generators.
As manufacturers strive to keep pace with the Moor's law, there is a continuing need for writers that can process large volumes of geometric figures, i.e., object features in design data, and produce precise patterns on work pieces. There is a need in the art to reduce the writing time while producing the needed precise pattern.